All About Circuits Forum  

Go Back   All About Circuits Forum > Electronics Forums > The Projects Forum


The Projects Forum Working on an electronics project and would like some suggestions, help or critiques? If you would like to comment or assist others with their projects, this is the place to do it.

Reply   Post New Thread
Thread Tools Display Modes
Old 06-03-2011, 06:27 PM
bhageria bhageria is offline
New Member
Join Date: Jun 2011
Posts: 2
Default use of darlington array


can anyone please explain me how to connect a uln2003 darlington array between ic 4017 an LEDs? please...
Reply With Quote
Old 06-03-2011, 06:35 PM
SgtWookie's Avatar
SgtWookie SgtWookie is offline
Expert Member
Join Date: Jul 2007
Location: In the vast midwest of the USA; CST
Posts: 22,039

Basically like in this schematic:

The ULN2804 is similar to the ULN2003, but it has 8 Darlington channels instead of 7 channels (so the pin numbers will be different after the 7th Darlington channel), and it has 10k resistors on the inputs instead of 2.7k like the ULN2003.

Since you are using the 2003 instead, you really should use 7.5k Ohm resistors between the 4017 outputs and the 2003 inputs; otherwise your 4017 outputs will be sourcing more current than they are specified for. You might "get away" without adding the resistors, at a penalty of decreased reliability.
Attached Images
File Type: gif Fig 11.4b.GIF (18.6 KB, 30 views)
General info:
If you have a question, please start a thread/topic. I do not provide gratis assistance via PM nor E-mail, as that would violate the intent of this Board, which is sharing knowledge ... and deprives you of other knowledgeable input.
Reply With Quote
Reply   Post New Thread


Related Site Pages
Section Title
Worksheet Summer and subtractor opamp circuits
Worksheet Conventional transistor overview and special transistors
Worksheet Insulated gate bipolar transistors
Worksheet Class B BJT amplifiers
Worksheet Design Project: Simple component curve-tracer circuit
Textbook Ring counters : Shift Registers
Textbook LED sequencer : Digital Integrated Circuits
Textbook The common-collector amplifier : Bipolar Junction Transistors
Textbook Junction field-effect transistors : Solid-state Device Theory
Textbook CMOS gate circuitry : Logic Gates

Similar Threads
Thread Thread Starter Forum Replies Last Post
ULN2003 Darlington Array Connections jack33 General Electronics Chat 2 01-07-2011 06:20 PM
Darlington Array IC question mxabeles General Electronics Chat 15 04-30-2010 01:57 AM
Darlington Transistor Array Manmeet Singh The Projects Forum 4 06-10-2009 04:19 AM
Question about NPN darlington pair transistor array sintau.tayua The Projects Forum 7 05-20-2009 05:52 AM
diode for Darlington array keithg The Projects Forum 1 01-27-2009 03:13 AM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 03:33 AM.

User-posted content, unless source quoted, is licensed under a Creative Commons Public Domain License.
Powered by vBulletin
Copyright ©2000 - 2014, vBulletin Solutions, Inc.